The father of a teenager who contracted brain-eating amoeba after rafting at the U.S. National Whitewater Center filed a lawsuit against the facility Monday on the one-year anniversary of her death.

The suit, filed in Ohio where Lauren Seitz lived, alleges the park’s popular rafting channels were dangerous and that park operators showed “conscious disregard for the safety of visitors.”

Seitz, 18, died of a rare brain infection caused by a single-celled animal, the amoeba Naegleria fowleri, days after visiting the center on June 8, 2016, with a church group. She was in a raft that overturned. The amoeba can infect a person when water goes up the nose and infections are rare, but almost always fatal.

The Whitewater Center attracts more than 800,000 visits a year and has total revenue exceeding $18 million annually. The 1,100-acre nonprofit facility in northwest Mecklenburg sits on county land, which it rents for $1 a year on a 40-year lease that ends in 2044.

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Under pressure, the park shuttered the water feature for nearly two months and a federal epidemiologist found that filtration and disinfection systems were inadequate to properly clean the facility’s turbid waters.

Water samples from the park detected the presence of an amoeba at levels the Centers for Disease Control and Prevention had not previously seen.

In response to those concerns, the park changed its filtration and disinfection system.

A Whitewater spokesman did not respond to attempts to reach him for comment Monday. The suit also names Colorado-based Recreation Engineering and Planning as a defendant. The company did not return a phone call seeking comment.

At the time of the teen’s death, the center was the only one of only three similar facilities in the U.S. that wasn’t regulated to protect the public from waterborne diseases.

A park employee wrote to a county commissioner to complain that the water quality had grown so poor that raft guides routinely suffered from staph infections, ringworm and other skin illnesses. Dead animals and trash were commonly found floating on the water’s surface, the employee said.

In October, Mecklenburg County commissioners required an annual operating permit from the county health department that can be suspended if the center doesn’t meet water-quality or safety standards.

Rules also give the health director the ability to declare conditions a public nuisance, which could trigger its shutdown.

The suit appears to take aim at one of the primary points of contention following Seitz’s death. Whitewater officials repeatedly defended themselves by saying that the amoeba is common in warm freshwater lakes and other bodies of water during the summer, particularly in the southern United States.

But attorneys for teen’s father cite a state review that concludes the “combination of high levels of N. fowleri and likelihood of submersion and exposure to high-velocity water results in a risk of infection that is likely higher than the risk of infection from exposure to N. fowleri in the natural environment.”